Manual shift control system for a multiple input-multiple output transmission

ABSTRACT

In combination with a transmission having both multiple input and output portions, each of which contains a plurality of speed change gears, is a manual shift control system having pluralities of both input and output shift rails that are adapted to cooperate with input and output cam shafts that extend through shift rail input and output cam shaft cutouts, with one or both cam shafts having at least one one-way cam which may be in combination with one or both of a two-way cam and an interlock cam, said one-way and two-way cams being adapted to cooperate with one-way and two-way cam follower surfaces, respectively, to effect bidirectional and unidirectional movement of the respective shift rails upon oscillation of the cam shafts, with the cam follower surfaces also being adapted to alternately cooperate with the interlock cams to arrest all but the selected ones of the input and output shift rails against axial movement. Details of actuating means and mechanical interlock means are also set forth.

RELATED APPLICATION

A U.S. patent application filed simultaneously herewith in the name ofRobert W. Wolfe, Ser. No. 853,073, filed Nov. 21, 1977, entitled "DoubleOscillating Motion--Single Linear Motion Cam" and assigned to thepresent assignee.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of art to which this invention pertains includes a shiftcontrol system in combination with a transmission having a multipleinput portion and a multiple output portion, each of which in turncontains a plurality of constant-mesh change speed gears to provide fora plurality of drive ratios in response to movement of an operator'sshift lever or the like.

2. Description of the Prior Art

My prior U.S. Pat. No. 4,000,662, which issued on Jan. 4, 1977 and isalso assigned to the assignee of the present invention, discloses ahighly advantageous form of transmission having a basic structure whichprovides axially aligned input and output shafts together with a singlealigned countershaft as well as first, second and third input gears anda plurality of forward output gears, with one of the forward outputgears also being capable of serving as one of the input gears. First,second and third driven countershaft gears are in constant mesh withrespective ones of the input gears and each one of a plurality ofdriving countershaft gears is in constant mesh with a separate one ofthe forward output gears, with one of the driving countershaft gearsalso being capable of serving as one of the driven countershaft gears.Multiple clutch means are utilized for selectively drivably connectingthe countershaft with one of the input gears and for selectivelydrivably connecting the output shaft with the countershaft.

The multiple use of most of the gears of this transmission together withthe triple input feature and the single countershaft permit utilizationof a transmission housing that has but two through bores, and in oneembodiment, all of the components for a nine speed forward and threespeed reverse transmission can be located completely within a standardfive speed forward--one speed reverse transmission housing.

My co-pending Application Ser. No. 731,391, filed Oct. 12, 1976, nowU.S. Pat. No. 4,068,537, issued Jan. 17, 1978, which again is assignedto the assignee of the present invention, discloses a sophisticatedshift control system of the preselector or semi-automatic type whereinshifts between drive ratios are made in response to the movement of anoperator's shift lever and the release of the torque on the drive train.

In order to both reduce the complexity and cost of the sophisticatedshift control system of my co-pending application, the present inventiontakes the form of a fully manual shift control system that permits easyshifting by the operator without the necessity, complexity or expense ofa power assist.

Prior art transmission control systems related to the present inventioninclude U.S. Pat. Nos. 1,118,389; 1,928,782; 3,487,713; 3,429,194;3,431,791; and 3,857,299.

SUMMARY OF THE INVENTION

This invention provides a manual control system for shifting a multipleinput--multiple output constant-mesh transmission in response tomovement of an operator's control lever or the like and, in someinstances, of a clutch pedal, to provide for a plurality of separatedrive ratios.

More particularly, the manual control system includes a plurality ofboth input and output shift rails that are used to effect speed changesand are controlled via spaced input and output cam shafts, respectively.One or both of the cam shafts include at least one oneway cam which maybe in combination with one or both of a two-way cam and an interlockcam, with all of the cams being selectively spatially arranged on eachcam shaft. Every input and output shift rail has axially spaced inputand output cam shaft cutouts in alignment with the input and output camshafts, respectively, so as to permit the transverse passagetherethrough of the cam shafts.

The output cam shaft cutouts of the input shift rails, as well as theinput cam shaft cutouts of the output shift rails, take the form ofclearance cutouts that permit the free lateral passage therethrough ofall of the cams as well as permitting the free axial movement of theshift rails without interfering with any cams located within theclearance cutouts. A two-way cam follower surface in a cam shaft cutoutis adapted to cooperate with its respective two-way cam to effect axialmovement of the respective shift rail in one direction upon clockwiseoscillation of the two-way cam and alternately to effect axial movementof the respective shift rail in an opposite direction uponcounterclockwise rotation of the two-way cam. The two-way cam followersurfaces are also adapted to alternately cooperate with an interlock camto arrest the respective shift rail against axial movement uponoscillation of the cams.

A further cam shaft cutout has a one-way cam follower surface adapted tocooperate with its respective one-way cam to effect axial movement ofthe shift rail in one and the same direction upon both clockwise andcounterclockwise oscillation of the one-way cam. These one-way camfollower surfaces are also adapted to alternately cooperate with aninterlock cam to arrest the respective shift rails against axialmovement upon oscillation of the cams.

The manual control system of this invention also includes means foractuating all of the cams by motion of a hand-actuated shift lever.Furthermore, interlock means cooperate with both the input and outputcams for actuating in unison all of the input cams and all of the outputcams in a predetermined sequential order. In addition, the pluralitiesof input and output shift rails are so arranged that the input andoutput interlock cams cooperate with all but the selected ones of theinput and output shift rails, thereby locking all but the selected shiftrails against axial movement.

In summary, the manual transmission control system of this invention canbe used with a transmission which must have at least two inputs and atleast two outputs, with the general arrangement of the shift controlsystem basically consisting of two sets of oscillating cams, one for theinput portion and the other for the output portion of the transmission.Both sets of cams are oscillated by motion of a hand-actuated shiftlever from a neutral position, in a predetermined sequential order,i.e., all of the output cams followed by all of the input cams or viceversa. For instance, in one example, when moving the hand lever forwardfrom neutral, first the output cams are oscillated rearward followed insequence by the input control cams oscillating rearward. Centering thehand lever knob back to neutral oscillates the cams back to neutral,first the input cams, then the output cams. This sequential action isprovided by an interlock system, with the actuating means causing thecams to move laterally right and left by opposite side or lateral motionof the knob of the shift lever to select the different shift rails.Subsequent axial or longitudinal movement of the shift lever then movesthe shift rail to select one of the two transmission settings availablein this shift gate.

Several embodiments of both the one-way and two-way cams together withthe respective shift rail cutouts and the interlock cams permit theassembly of different combinations so that almost any desired shiftpattern can be obtained.

The various features and advantages of this invention will be morereadily understood by persons skilled in the art when following thedetailed description in conjunction with the several drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a multiple input-multiple output transmission inwhich the shift control system of this invention finds utility;

FIG. 2 is a schematic showing of the power paths through thetransmission in each of the forward and reverse speeds;

FIG. 3 is a side view, with portions broken away, looking in thedirection of arrows 3--3 in FIG. 5, of the transmission control systemand more particularly, the manually-actuated control cover of thetransmission control system;

FIG. 4 is a schematic showing of the shift pattern that is achieved viathe control system of this invention;

FIG. 5 is a simplified top plan view of the control cover of FIG. 3;

FIG. 6 is a simplified end view of the input cams of the control systemof this invention as mounted on an input cam shaft sleeve;

FIG. 7 is a simplified end view of the output cams of the control systemof this invention as mounted on an output cam shaft sleeve;

FIGS. 8a,b,c,d illustrate several operational modes of a two-way cam inconjunction with associated cam follower notches;

FIGS. 9a,b illustrate two operational modes of a one-way cam inconjunction with associated cam follower notches; and

FIG. 10 illustrates a shift rail having an interlock cam positionedwithin a cam follower surface and a two-way cam positioned within ashift rail clearance cutout.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in detail, the specific transmission 10shown in FIG. 1, which can be used with the transmission control systemof this invention, is substantially identical to transmission 10 shownin my prior U.S. Pat. No. 4,000,662 that is also assigned to theassignee of this invention. For ease of understanding, however, thestructure and function of transmission 10, which has a plurality ofconstant-mesh change speed gears, will again be described hereinafter.

Transmission 10 includes a casing or housing 12, an input shaft 14rotatably journalled therein and an output shaft 18 axially aligned withthe input shaft and rotatably journalled relative to the input shaft andcasing 12. A countershaft 30 is parallel to and vertically displacedbelow output shaft 18, while a dead shaft 34, parallel to countershaft30, is fixedly retained in aligned bosses or stub walls 36 in casing 12.

Shaft 14 has a gear 40 affixed thereto or integral therewith, with gear40 being in constant mesh with gear 42 rotatably journalled oncountershaft 30. A conventional dog clutch 34, incorporating a knownclutch lock to prevent jumping out of gear, is disposed on the hub ofgear 32 and is arranged either to drivably connect gear 32 tocounter-shaft 30 for conjoint rotation therewith, or to occupy a neutralposition as shown in FIG. 1.

Input shaft tubular portion 22, which is adjacent the inner axial end ofgear 40, has either affixed thereto or integral therewith, one end ofthe sleeve 48 that coaxially surrounds output shaft 18, with sleeve 48forming an extension of the input shaft.

Rotatably journalled on sleeve 48 is a gear 58 that is in constant meshwith a further gear 60 integral with or affixed to countershaft 30.Rotatably journalled on output shaft 18, adjacent to the inner end ofsleeve 48, is a gear 64 that is in constant mesh with a gear integralwith or affixed to countershaft 30. Another conventional clutch 68, suchas a dog clutch, and also incorporating a clutch lock, is disposed onsleeve 48 between gears 58 and 64 and is arranged either to drivablyconnect gear 58 to sleeve 48, or to drivably connect gear 64 to sleeve48, or to occupy a neutral position as shown in FIG. 1. Thus, basically,it is the function of clutch 68 to connect either of gears 58 and 64 forconjoint rotation with input shaft 14 via sleeve 48. Gears 40, 58 and64, whose pitch circle diameters differ from one another in a well knownmanner are thus in constant mesh with gears 42, 60 and 66, respectively,with the utilization of clutches 44 and 68 thus providing three separateinputs to single countershaft 30. The portion of transmission 10described so far may be designated the "input" portion of thistransmission.

Also journalled for rotation on output shaft 18 are gears 70, 72 and 74whose pitch circle diameters differ from one another in a well knownmanner, with gears 70 and 74 being in constant mesh, respectively, withgears 76 and 78 affixed to or integral with countershaft 30. Gear 76,which has a greater axial extent than gear 70, is also in mesh with agear 82 affixed to or forming part of a tubular reverse-idler shaft 80which in turn is journalled for rotation on dead shaft 34. Gear 72 is inconstant mesh with a gear 84 which is affixed to or forms a part ofshaft 80.

A further conventional clutch 88, such as a dog clutch, and alsoincorporating a clutch lock and a known synchromesh device 90, isdisposed on output shaft 18, intermediate gears 64 and 70, and isarranged to drivably connect either of these two gears to shaft 18 or tooccupy a neutral position as shown in FIG. 1. A similar conventionalclutch 92, incorporating a clutch lock and a known synchromesh device94, is disposed on output shaft 18, intermediate gears 72 and 74, and isarranged to drivably connect either of these gears to shaft 18 or tooccupy a neutral position as shown in FIG. 1. A typical prior artsynchromesh device is disclosed in U.S. Pat. No. 2,667,955 which issuedto L. A. Bixby on Feb. 2, 1954.

Basically, gears 64, 70, 72 and 74, together with gears 66, 76, 82, 84and 78, may be described as constituting the "output" portion oftransmission 10. It should be noted that gears 64 and 66 can alternatelyfunction both as input and output gears, as will be explained in moredetail as this description progresses.

In operation, transmission 10 has nine forward speeds and as many asthree reverse speeds, although not all of the three reverse speeds needbe utilized. FIG. 2 is a schematic showing of the various power pathsthrough transmission 10 in each of the forward and reverse speeds. Asbest seen in FIGS. 1 and 2, transmission 10 can be defined as having afirst input via constant mesh gears 40 and 42, with the latter beingadapted to be coupled to countershaft 30 via clutch 44, withcountershaft 30 rotating in a direction opposite to that of input shaft14. A second input is provided by constantly meshing gears 58 and 60,with the former being adapted to be coupled to input sleeve 48 via oneof the operative positions of clutch 68, thereby causing the rotation ofcountershaft 30 in a direction opposite to that of input shaft 14. Yetanother or third input is provided by constantly meshing gears 64 and66, with the former being adapted to be coupled to input shaft sleeve 48via the other operative position of clutch 68, thereby rotatingcountershaft 30 in a direction opposite that of input shaft 14.

A first forward output from transmission 10 can be defined by constantlymeshing gears 78 and 74, with the latter being adapted to be coupled tooutput shaft 18 via one of the operative positions of clutch 92, therebyrotating output shaft 18 in a direction opposite to that of countershaft30. A second forward output is defined by constantly meshing gears 76and 70, with the latter being adapted to be coupled to output shaft 18via one of the operative positions of clutch 88, thereby rotating outputshaft 18 in a direction opposite to that of countershaft 30. Yet anotheror third forward output is defined by constantly meshing gears 66 and64, with the latter being adapted to be joined to output shaft 18 viaanother of the operative positions of clutch 88, thereby again rotatingoutput shaft 18 in a direction opposite to that of countershaft 30.

A reverse output is provided by constantly meshing gears 84 and 72, withthe latter being adapted to be coupled to output shaft 18 via another ofthe operative positions of clutch 92, thereby rotating output shaft 18in the same direction as countershaft 30 (and in a direction oppositethat of input shaft 14).

An analysis of FIG. 2 will show that by utilizing the first input(40,42) together with the first output (78,74) provides a first forwardspeed. Continuing the use of the first input but utilizing the second(76,70) or third (66,64) outputs will provide second or third forwardoutput speeds. The third input (64,66) together with the first outputprovides a fourth forward speed, whereas the second input (58,60) withthe first output provides a fifth forward speed. The third inputtogether with the second output provides a sixth forward speed whereasthe second input together with the second output provides a seventhforward speed. The third input, which can also be the third output,provides an eighth or direct forward drive by utilizing clutch 68 tocouple one side of the hub of gear 64 to input shaft sleeve 48 and byutilizing clutch 68 to couple the other side of the hub of gear 64 tooutput shaft 18. A ninth forward speed is provided by utilizing thesecond input together with the third output.

Three reverse speeds are available by coupling any of the first, secondor third inputs to the reverse output (84,72). While three reverseoutputs are possible, it is, of course, not necessary that all three ofthe speeds be utilized.

Another way of defining the structure and function of transmission 10is, as best seen in FIG. 2, that the first input is utilized in thefirst, second and third speeds as well as the first speed in reverse.The second input is utilized for the fifth, seventh and ninth speedsforward as well as the third speed in reverse. The third input isutilized for the fourth, sixth and eighth speeds forward as well as thesecond speed in reverse. The first output is utilized for the first,fourth and fifth speeds forward, whereas the second output is utilizedfor the second, sixth and seventh speeds forward. The third output isutilized for the third, eighth and ninth speeds forward, while thereverse output is utilized for the first, second and third speeds inreverse.

While transmission 10 has three inputs and three outputs, it should benoted that when changing from first to second, second to third, fourthto fifth, sixth to seventh and eighth to ninth speeds forward, only oneclutch has to be disengaged and one other clutch has to be engaged,whereas in changing from third to fourth, fifth to sixth and seventh toeighth speeds forward, two clutches must be disengaged and two otherclutches must be engaged. The shifts between first, second and thirdreverse speeds require the disengagement of one clutch and theengagement of one other clutch.

A shift control system, generally designated by numeral 98 and best seenin FIGS. 3 and 5, for manually selecting any of the available powerpaths through the transmission, includes four shift forks or selectorelements 1', 2', 3' and 4'. Shift forks 1', 2' and 3' are rigidlyattached to one or more shift rails 1", 2" and 3" as will be explainedin more detail as this description progresses. Shift fork 4' (best seenin FIG. 1) is pivotally connected at about its midpoint to casing 12 andhas a socket portion 114 attached to a lug member 116 (FIG. 3) which inturn is rigidly connected with one or more shift rails 4". Shift fork 4'operatively engages clutch 44 and operates it in a manner previouslydescribed. Similarly, shift forks 1', 2' and 3' operatively engageclutches 92, 88 and 68, respectively. In the interest of simplicity andin order to avoid confusion, the engagement of the shift forks withtheir respective clutches is not shown, but is accomplished in a mannerwell known in the art, an example of which is shown in my prior U.S.Pat. No. 4,000,662.

Shift control system 98 includes a control cover 118 whose control coverhousing 120 fits over transmission 10 and is rigidly bolted totransmission housing 12. Pluralities of parallel shift rails 1", 2", 3"and 4" are slidably supported in control cover housing 120, for axialmovement relative thereto, on support pads 122. Shift rails 1" and 2"which are associated with shift forks 1' and 2', respectively, may bedenominated as the output shift rails since they serve to actuate outputclutches 92 and 88, respectively. Similarly, shift rails 3" and 4",which are associated with shift forks 3' and 4', respectively, may bedenominated as the input shift rails since they serve to actuate inputclutches 68 and 44, respectively. Since clutches 68, 88 and 92 have aneutral position and an operative position on either side of neutral,each one of shift rails 1", 2" and 3" is provided with three notches 126that can cooperate with a spring loaded detent 128 in order to positionthe shift rails to any one of the three positions. Shift rails 4" areonly provided with two notches 126 since clutch 44 has but one operativeposition in addition to its neutral position.

Each one of the shift rails is provided with two axially spaced shiftrail cutouts 130, 132 which may be termed as the input and outputcutouts, respectively. Extending through shift rail cutouts 130 and 132are fixed input and output cam shafts 136, 138, respectively. Slidinglysecured on cam shafts 136 and 138, for lateral and oscillating movement,are split tubes or shafts 140 and 142, respectively. Affixed to one endof tube 140, via tang 146, is one end of an input lever 144. Similarlyaffixed to the other end of split tube 142 is one end of an output lever148 (best seen in FIGS. 5 and 7).

Control cover housing 120 is provided with a top cover portion 150having a generally circular opening 152. Located within control coverhousing 120, below top cover portion 150, is a laterally movablemounting plate 154 having a large central opening 156 as well as a pairof diagonally spaced longitudinal slots 158 and 160. Slidably secured,for axial movement, on mounting plate 154 are opposed input and outputlinks 162 and 164. Input link 162 has a cutout 166, aligned withmounting plate slot 158, which is adapted to receive the free end ofinput lever 144. Similarly, output linked 164 has a cutout 168, alignedwith mounting plate slot 160, which is adapted to receive the free endof output lever 148. Extending across mounting plate central opening 156is a differential link 172 whose ends 174, 176 are received in opposedcutouts 178, 180 of links 162, 164, respectively. In addition,differential link 172 is provided with an aperture 182 that is adaptedto receive the lower ball 186 of a shift lever 184 whose mounting ball188 is pivoted at 190 for pivotal movement about two perpendicular axes.Also extending across mounting plate central opening 156, and slidablysecured for lateral movement on mounting plate 154, is a sequentialinterlock pin 192 having opposed ends 194 and 196 that are adapted toalternately engage in one of notch 198 in link 162 and in one of axiallyspaced nothes 200, 202 in link 164, respectively.

As previously noted, and as best seen in FIG. 3, each one of shift rails1", 2", 3" and 4" is axially movable, with this movement beingaccomplished either via a two-way or A cam or a one-way or B cam. An Acam has one or two vertically opposed operating cam surfaces A_(U)(Upper) or A_(L) (Lower), one of which will enter a single cam followernotch A'_(U) or A'_(L) (either in the upper or lower portion of camfollower inner peripheral surface A' of shift rail cutout 130 or 132),depending on the desired direction of shift rail movement. See FIGS.8a,b. While there can be both A_(U) and A_(L) operating surfaces on oneA cam (FIG. 8c), there can be but a single notch, either A'_(U) orA'_(L) in surface A' of rail cutouts 130, 132, since otherwise therewould be rotation rather than the desired axial movement. Converselythere can be two notches A'_(U) and A'_(L) in surface A' of one railcutout (FIG. 8d) if they are separately alternately actuated by single Acams. The direction of movement of the shift rail can, of course,vertically displace both the cam operating surface and the cam followernotch by 180°. Thus, the cams axially actuate the shift rails in amanner akin to cam followers.

One-way or B cams are unidirectional cams that can be actuatedbidirectionally, i.e., either clockwise or counterclockwise, that willmove the shift rail in the same direction regardless of the same oropposite directional input and upon centering movement return the cam toneutral position. B cams can be of two types, namely B_(F) (Front) orB_(R) (Rear) as best shown in FIGS. 9a, b. Cams B_(F) and B_(R) areallochiral in shape with each B cam having identical upper and lower camoperating surfaces 204 which include tooth portions 206, connectingsurface 205 and cam end surfaces 208. Surfaces 205 and 208 meet atintersection 210. Center points 211 of cam end surfaces 208 and leadingedges 213 of tooth portions 206 are offset relative to the verticalcenter line of cam shaft 138 (or 136) since a large vertical movement ofintersection 210 is necessary to allow the engaging and disengaging ofsurface 208 with respect to cam follower notches B'_(F) in both theupper and lower portions of cam follower inner peripheral surfaces B' ofshift rail cutouts 130 and 132. Each cam follower notch B'_(F) has ashift rail advancing surface 207 adapted to cooperate with tooth edge213 and a shift rail disengaging surface 209 adapted to cooperate withcam end surface 208. For example, in a clockwise actuation of cam B_(F),the lower cam tooth 206 initially engages shift rail advancing surface207 of and, upon continued rotation of cam B_(F), will axially slide theshift rail forwardly or to the left from neutral. As this movementoccurs, intersection 210 and lower cam rear surface 208 will also enterlower notch B'_(F) so that there is basically a rigid mechanicalconnection between cam B_(F) and the shift rail, with cam lower rearsurface 208 then interacting with shift rail disengaging surface 209 tocause the shift rail to return to neutral upon centering oscillation ofthe cam. On the other hand, if cam B_(F) is actuated in thecounterclockwise direction, movement of the shift rail will still beforwardly or to the left except that there is interaction between theupper cam surface 206 and the upper notch B'_(F) in the manner similarto that previously described. The direction of movement of the shiftrail can, of course, be reversed by reversing both cam B and camfollower surface B'. As previously noted, each shift rail is providedwith two or more notches 126 that cooperate successively with springloaded detent 128 in order to positively position the shift rail to oneof its operating or neutral positions. It is important that each shiftrail be positively held in its neutral position in order to avert anyunwanted axial movement of the shift rail. For example, it isconceivable that due to unavoidable manufacturing tolerances there couldpossibly be a hangup of B cam intersections 210 with adjacent arcuatesurface portions 217 of cam follower surface B' which could produce theundesired result of locking cam B against rotation.

It should be understood that even though each one of the various shiftrails has two shift rail cutouts 130, 132 only one of those cutouts isprovided with the necessary cam follower surface and cam followernotches for cooperation with either cam A or B, and the remaining cutoutis a clearance cutout 134 (FIG. 10) whose inner peripheral surfacedimensions are such as to permit the free lateral passage therethroughof cams A and B as well as to permit the free axial or reciprocalmovement of the shift rail without interference with any cams locatedwithin the clearance cutout. A portion of clearance cutout 134 is shownin FIG. 3.

Since there are two input clutches 44 and 68 as well as two outputclutches 88 and 92, selection and consequent actuation of one of theinput and output clutches should be accompanied by interlock of thenonselected ones of the input and output clutches to prevent unwantedactuation thereof. This interlocking function can best be accomplishedby an interlock or I cam (FIGS. 3 and 10) which takes the form of ahorizontally extending opposed-lobe cam whose lobes 212 are adapted toabut the opposed sides 214, 216 and 218, 220 of cam follower surfaces A'and B', respectively, thereby arresting the associated shift railagainst all axial movement. At the same time, however, the location ofan I cam in a clearance cutout 134 will still permit free reciprocalaxial movement of the shift rail. See FIG. 10.

Each one of cams A, B and I are affixed to split tubes 140 or 142 viatangs and therefore are laterally movable with and oscillate with tubes140 or 142. If desired, the cams could be mounted directly on cam shafts136 or 138 if the cam shafts are constructed to be capable of both axialand oscillating movements. A combination of these previously describedthree types of cams with a sufficient number of shift rails can producemost any desired type of shift pattern, an example of which will now bedescribed.

The design of a shift control system for a multiple input--multipleoutput transmission starts with the drawing up of a desired shiftpattern of the type shown in FIG. 4. Thereafter, the positions of boththe input and output elements (the shift forks) are determined for eachof the shift positions in the shift pattern together with thedirectional movement, from neutral, of the particular clutch controlledby the particular shift fork to arrive at the desired shift pattern.FIG. 4 also shows, via pointed ends 224, the direction of movement ofthe selector elements from the neutral position, with shift forks 1', 2'respresenting the output elements that control output clutches 92 and88, whereas forks 3' and 4' represent the input elements that controlinput clutches 68 and 44, respectively.

Once the shift pattern and selector element positions have beenestablished in the manner shown in FIG. 4, then the proper selection ofthe various shift rails and the necessary types of cams can bedetermined. For example, looking first at the input portion oftransmission 10, since shift fork 4' controls the inputs for speeds 1and reverse in shift gate 254, as well as the inputs for speeds 2 and 3in adjacent shift gate 255, two input rails 4" are required for shiftfork 4'. A perusal of FIG. 4 will show that the direction of movement ofshift fork 4' is the same for speeds 1 and reverse, therefore, a one-wayor B cam is required. Since the direction of movement is forward (or tothe left), a B_(F) cam is required. The same reasoning holds for speeds2 and 3, and, therefore, another B_(F) cam is required, with the resultthat a B_(F) cam is required for each of the two 4" shift rails. CamsB_(F) must be mounted on input cam shaft split tube 140 since shift fork4' controls input clutch 44. Naturally, each one of shift rails 4" musthave cam follower notches B'_(F) and the shift rail cutout around outputcam shaft 138 must be of clearance of type 134.

Shift fork 3' controls inputs for speeds 4,5; 6,7; and 8,9. Therefore,three separate input shift rails 3" are required. Since the direction ofmovement of shift fork 3' for speeds 4 and 5 is opposite, a two-way or Acam is required. Furthermore, since the direction for speed 4, which isselected first, is to the right (or to the rear), an A_(U) cam isrequired because it will first shift to the rear when actuated in onedirection and thereafter shift to the front when actuated in theopposite direction. A further analysis of FIG. 4 will show that theremaining two shift rails 3' for speeds 6 and 7, as well as 8 and 9,will also require A_(U) cams as well as A'_(U) cam follower notches inshift rail cutouts 130. Again, shift clearance cutouts 134 are requiredin shift rails 3" around output cam shaft 138.

Shift fork 2' controls the transmission outputs for speeds 2 and 3, also6 and 7, as well as 8 and 9. Therefore, three shift rails 2" arerequired, with a B_(R) cam being necessary for speeds 6 and 7, while aB_(F) cam is necessary for speeds 8 and 9. Furthermore, and again basedon the criteria and reasoning previously set forth, an A_(U) cam isrequired for the control of the output elements of speeds 2 and 3.

Shift fork 1', which controls the output element for speeds reverse and1, as well as 4 and 5, requires two output shift rails 1". Since thedirection of movement of shift fork 1' is opposite for speeds reverseand 1, an A_(L) cam is required. The direction of movement of shift rail1' for the output elements of speeds 4 and 5 is the same, therefore, aB_(R) cam is necessary. It should be understood that corresponding camfollower notches are required for coaction with their respective cams,and that shift rail clearance cutouts 134 are required in all outputshift rails in the areas around input cam shaft 136. All output cams arearranged on output cam shaft split tube 142.

The actual physical arrangement of these various input and output rails,as well as the physical arrangement of the various A, B and I camsshould be accomplished in a manner so as to minimize the required numberof cams, i.e., preferably the cams should be used more than once.

Referring now specifically to FIGS. 5, 6 and 7, FIG. 5 shows anarrangement of pluralities of shift rails 1", 2", 3" and 4" arranged ina manner so as to accomplish the shift pattern set forth in FIG. 4. Theleft end portion of FIG. 5 shows multiples of input shift rails 3" and4" together with a notation of each applicable cam follower notch (suchas B'_(F) and A'_(U)) together with the designation of the speedscontrolled by the particular shift rail (such as 2, 3 for example).Interaction of the input shift rails with the input cams is shown inphantom line connections with FIG. 6, and it can be seen that a singleB_(F) cam is utilized to actuate both the 4" shift rails, whereas asingle A_(U) cam is utilized to actuate all three of the 3" inputs shiftrails. It should, of course, be understood that all shift rails of onetype, such as, for example, all three of shift rails 3", are tiedtogether and move as a unit. FIG. 5 also shows that shift rail clearancecutouts 134 are utilized on all input shift rails at the output camshaft location and similar cutouts 134 are utilized on all output shiftrails at the input cam shaft location in order to permit free passage ofthe corresponding cam shafts and their associated cams.

FIG. 6 shows the required input cams, namely A_(U) and B_(F), togetherwith three interlock cams I and input lever 144, all of which arespatially arranged on split tube 140. Arrow 226 in FIG. 6 denotes thatinput cam shaft split tube 140 can move laterally in order to permitshifting each of the five transmission shift gates (254-258) shown inFIG. 4, with these gates being indicated in FIG. 6. However, input camshaft split tube 140, in FIG. 6, is aligned with the 4-5 shift gateposition wherein cam A_(U) is located in the 3" shift rail, denominatedby numeral 228, that serves for selecting speeds 4 and 5 via inputclutch 68. At the same time, cam B_(F) is located in a clearance cutout134 denominated by the numeral 230, while an interlock cam I,denominated by numeral 232, is located in a shift rail 4", denominatedby numeral 234, to arrest shift fork 4', and therefore input clutch 44against movement.

Turning now to the right end portion of FIG. 5, there can be seen theforeshortened end portions of multiples of output shift rails 1" and 2",together with their associated cam follower notch designations, as wellas the designations of the speeds controlled by the particular shiftrail. Phantom line connections between FIGS. 5 and 7 show theinteractions of the various shift rails and cams. Similar to FIG. 6,FIG. 7 shows the required output cams, namely A_(UL), B_(F) and B_(R),together with two interlock cams I and output lever 148, all of whichare spatially arranged on split tube 142. Arrow 236 in FIG. 7 againdenotes that output split tube 142 can move laterally in order to permitshifting of each of the five transmission shift gates shown in FIG. 4,with these gates again being indicated in FIG. 7. However, output camshaft split tube 142, in FIG. 7, is aligned with the 4-5 speed gateportion, wherein cam B_(R) is located in the 1" shift gate, denominatedby numeral 238 that serves for selecting speeds 4 and 5 via outputclutch 92. At the same time, cam A_(UL) is located in clearance cutout134 denominated by numeral 240, while an interlock cam I, denominated bynumeral 242, is located in a shift rail 2", denominated by numeral 244,to arrest shift fork 2' and therefore output clutch 88, againstmovement. In addition, cam B_(F) is located in the clearance cutout 134denominated by numeral 246. It should be noted that an output shift rail2", denominated by numeral 244, and an adjacent output rail 1",denominated by numeral 248, even though they require two-way cams A_(U)and A_(L), respectively, are served by a single A_(UL) cam since onlyone of the A'_(U) or A'_(L) cam follower notches is used in shift rails244 and 248.

Turning now to the operation of shift control system 98, it should benoted that system 98 must be used with a transmission which has a geartrain that is characterized by at least two inputs and at least twooutputs, an example of which is prior art transmission 10. The generalarrangement of shift control system 98 basically consists of two sets ofoscillating cams, one for the input portion of the transmission and theother for the output portion of the transmission. Both sets of cams areoscillated by motion of a hand-actuated shift lever (partially shown at184) from a neutral position, but in a predetermined sequential order,e.g., in moving the hand lever knob forward from neutral, first theoutput control cams are oscillated rearward followed in sequence by theinput control cam oscillating rearward. Centering the hand lever knobback to neutral oscillates the cams back to neutral, first the inputcams followed by the output cams. This sequential action is provided byan interlock system generally denominated by numeral 250, which forms aportion of shift control system 98. Interlock system 250 includesdifferential link 172 which is actuated by lower ball 186 of shift lever184. Differential link 172 sequentially controls input link 162,connected to split input tube 140 via input lever 144, and output link164, connected to output split tube 142 via output lever 148. The inputcams on tube 140 and the output cams on tube 142 are moved laterallyright and left by opposite side or lateral motion of the knob of shiftlever 184 which will ultimately be used to select different rails toprovide the proper motion to the various shift forks in the transmissionin the manner already indicated. Sequential interlock pin 192, whenshifting from neutral, always permits initial movement of the outputcams followed by the input cams, with this procedure being reversed whenmoving shift lever 184 back to neutral. It should be understood that thementioned sequential order, i.e., output cams followed by input cams, isnot mandatory and may be reversed, depending on the basic transmissiondesign. Furthermore, the cam shafts need not be restricted to beingeither input or output cam shafts exclusively, but a single cam shaftcould also be used to operate both input and output rails. It shouldalso be clear at this time that lateral or transverse motion of shiftlever 184 permits selection of the proper shift gate, and therefore thedesired shift rail while axial or longitudinal movement of shift lever184 then axially moves this shift rail to select one of the twotransmission settings controlled via this shift gate.

As previously noted, a two-way or A cam will move a shift rail in onedirection and return it to neutral as the shift lever is moved in onedirection then returned to neutral, with this direction being reversibleby moving the cam follower notch from a top to a bottom position of viceversa for use with A_(U) or A_(L) cams. One-way or B cams areunidirectional cams that can be actuated clockwise or counterclockwisesince there are both upper and lower cam surfaces; however, regardlessof the direction of actuation, the cam will always move in the samedirection, and a subsequent centering always brings the shift rail backto neutral. Basically, a B cam can change a double oscillating motioninto a single linear motion. This type of motion is necessary, forexample, when shifting from 4th to 5th, where output clutch 92 is usedfor both gear settings. Thus, when shifting from a neutral position 252in FIG. 4 to 4th gear, or when shifting from neutral to 5th gear, inboth instances shift fork 1' and shift rail 238 (FIG. 5) will move tothe rear, although in the 4th gear actuation the input is in onedirection, whereas in the 5th gear actuation the input is in the otherdirection. Therefore, regardless as to whether the input is clockwise orcounterclockwise, one-way cam B_(R) will move its associated shift railto the rear. Again, depending on the direction of the required shiftrail movement, either B_(F) or B_(R) cams can be utilized.

Interlock or I cams are utilized to abut the opposing sides of the camfollower surfaces of the shift rails of the nonselected ones of the atleast two input and at least two output clutches.

By combining these three types of cams with a sufficient number of shiftrails, almost any desired shift pattern may be obtained, an example onlyof which has been illustrated herein with reference to known nine speedforward and three speed reverse transmission 10.

The shift control system of this invention finds utility in at least twotypes of transmission operation. The first of these is with atransmission that is fully synchronized. In this type of operation, theinitial phase of the shift (usually the output portion of thetransmission) will synchronize only some parts within the transmission,and in the lower gears, only a part of the reduction ratio. This resultsin easy shifting. The final part of the shift (usually the input portionof the transmission) synchronizes the clutch, but again it is only apart of the total gear ratio, so that the shifting is again easy. Thiseasy shifting more than compensates for the decreased mechanicaladvantage on the shift lever that is necessitated by the sequentialshift.

The shift control system of this invention also finds utility intransmissions where a large number of speeds are used in a heavy vehicleand the operation of a heavy clutch pedal becomes a burden to theoperator. In this second type of operation, the last portion of theshift (regardless of whether it is the input or output portion of thetransmission) is not synchronized but rather has relatively coarse,flat-ended clutching teeth which will not engage unless nearlysynchronized. In this type of operation, the shift fork, instead ofbeing rigidly attached to the shift rail, is axially movable on the railbut urged to a normal position by a preloaded spring. The in-gear detentmust be strong enough to hold the rail in position against the force ofthe preloaded spring, with the actual shift not taking place until theoperator synchronizes that engine by manipulation of the throttle. Asimilar type of preloading is disclosed in U.S. Pat. No. 2,839,940 to A.C. Bryan which issued on June 24, 1958. The shift itself can be madequieter and smoother by adding a blocking ring which holds the engagingteeth a small distance away from each other when they are notsynchronized, but unblocks them when the operator has manipulated theengine through synchronous speed. A shift blocker mechanism of this typeis set forth in my prior art U.S. Pat. No. 4,027,756 which issued onJune 7, 1977. However, this type of blocker cannot be used for ratiosthat are used for engaging a clutch when the vehicle is completelystationary.

From the foregoing, it is believed that those familiar with the art willreadily recognize and appreciate the novel concepts and features of thepresent invention, and it is thought that the invention will have beenclearly understood from the foregoing detailed description of mynow-preferred illustrated embodiment. Obviously, while the invention hasbeen described in relation to only one preferred embodiment, numerousvariations, changes and substitutions of equivalents will presentthemselves to persons skilled in the art and may be made withoutnecessarily departing from the scope and principles of this invention.As a result, the embodiment described herein is subjected to variousmodifications, changes and the like, without departing from the scopeand spirit of the invention. Consequently, the scope of this inventionshould be determined solely by reference to the claims appended hereto.

What is claimed is:
 1. In combination with a speed change transmissionhaving a gear train that is characterized by having at least two inputsand at least two outputs and having pluralities of input and outputshift rails to effect speed changes; transmission control comprising:a.first and second spaced, parallel shafts, said shafts being capable ofboth axial and oscillating movements; b. first and second two-way cams;c. first and second one-way cams; d. first and second interlock cams,with all of said first and all of said second cams being selectivelyspatially arranged on said first and second shafts, respectively, so asto slide and oscillate in unison therewith, said first and second camsbeing adapted to cooperate with one or the other of said input andoutput shift rails; e. every input and output shift rail having axiallyspaced first and second cutouts in alignment with said first and secondshafts, respectively, so as to permit passage therethrough of saidshafts, with said input shift rail second cutouts as well as said outputshift rail first cutouts taking the form of clearance cutouts thatpermit the free lateral passage therethrough of all of said cams as wellas permit the free axial movement of said shift rails withoutinterfering with any cams located within said clearance cutouts; f. atwo-way cam follower surface in at least one input shift rail firstcutout as well as at least one output shift rail second cutout adaptedto cooperate with their respective two-way cams to effect axial movementof the respective shift rails in one direction upon clockwiseoscillation of said two-way cams and alternately to effect axialmovement in an opposite direction upon counterclockwise rotation of saidtwo-way cams, said two-way cam follower surfaces also being adapted toalternately cooperate with said interlock cams to arrest the cooperatingshift rail against axial movement upon oscillation of said cams; g. aone-way cam follower surface in at least one other input shift railfirst cutout as well as at least one other output shift rail secondcutout adapted to respectively cooperate with said respective one-waycams to effect axial movement of the respective shift rails in one andthe same direction upon both clockwise and counterclockwise oscillationof said one-way cams, said one-way cam follower surfaces also beingadapted to alternately cooperate with said interlock cams to arrest saidcooperating shift rail against axial movement upon oscillation of saidcams; h. means for actuating, via sliding and oscillating, all of saidcams by motion of a hand-actuated shift lever; i. interlock system meansbetween said first and second cams for actuating in unison all of saidfirst cams and all of said second cams in a predetermined sequentialorder; and j. said plurality of input and output shift rails beingarranged so that said first and second interlock cams cooperate with thenonselected ones of the input and output shift rails of said at leasttwo transmission inputs and at least two transmission outputs.
 2. Thetransmission control system of claim 1 wherein each one-way cam includessubstantially similar vertically opposed cam operating surfaces, each ofwhich has a tooth portion and a cam end surface.
 3. The transmissioncontrol system of claim 2 wherein each one-way cam follower surfaceincludes substantially similar vertically opposed cam follower notches,with each notch in turn having a shift rail advancing surface and ashift rail disengaging surface.
 4. The transmission control system ofclaim 3 wherein the center points of said cam end surfaces and theleading edges of said tooth portions are offset relative to a verticalcenter line of the associated one of said shafts in order to permitinteraction of said cam end surface with respect to said shift raildisengaging surface.
 5. The transmission control system of claim 3wherein said one-way cams and said one-way cam follower surfaces aresymmetrical about a horizontal plane containing the axes of said shafts.6. The transmission control system of claim 3 wherein each one-way camfollower surface includes opposed side surfaces that are adapted tocooperate with one of said interlock cams in the absence of a one-waycam.
 7. The transmission control system of claim 6 wherein each of saidinterlock cams includes a pair of opposed lobes that are adapted tocooperate with said opposed side surfaces.
 8. The transmission controlsystem of claim 1 where each two-way cam includes at least onevertically disposed cam operating surface.
 9. The transmission controlsystem of claim 8 wherein each two-way cam follower surface includes atleast one vertically disposed cam follower notch adapted to cooperatewith the operating surface of said two-way cam.
 10. The transmissioncontrol system of claim 9 wherein each two-way cam follower surfaceincludes opposed side surfaces that are adapted to cooperate with one ofsaid interlock cams in the absence of a two-way cam.
 11. Thetransmission control system of claim 1 wherein all of said first camsand all of said second cams are adapted to cooperate with said input andoutput shift rails, respectively.
 12. The transmission control system ofclaim 11 wherein said interlock means always permits initial movement ofall of said first cams followed by all of said second cams, whenshifting from neutral, with this procedure being reversed when shiftingback to neutral.
 13. In combination with a speed change transmissionhaving a gear train that is characterized by having multiple inputs andmultiple outputs, a transmission control comprising:a. pluralities ofinput and output shift rails to effect speed changes; b. spaced,parallel, fixed input and output cam shafts; c. at least one input andone output two-way cam; d. at least one input and at least one outputone-way cam; e. at least one input and at least one output interlockcam, will all of said input and output cams being selectively spatiallyarranged on said input and output cam shafts, respectively, so as toslide thereon and oscillate in unison relative thereto; f. every inputand output shift rail having axially spaced input and output cam shaftcutouts in alignment with said input and output cam shafts,respectively, so as to permit the passage therethrough of the said camshafts, with the output cam shaft cutouts of said input shift rails aswell as the input cam shaft cutouts of said output shift rails takingthe form of clearance cutouts that permit the free lateral passagetherethrough of all of said cams as well as to permit the free axialmovement of said shift rails without interfering with any cams locatedwithin said clearance cutouts; g. an input cam shaft cutout in at leastone input shift rail as well as an output cam shaft cutout in at leastone output shift rail having a two-way cam follower surface adapted tocooperate with their respective two-way cams to effect axial movement ofthe respective shift rails in one direction upon clockwise oscillationof said two-way cams and alternately to effect axial movement of therespective shift rails in an opposite direction upon counterclockwiserotation of said two-way cams, said two-way cam follower surfaces alsobeing adapted to alternately cooperate with said interlock cams toarrest the respective shift rails against axial movement uponoscillation of said cams; h. an input cam shaft cutout in at least oneother input shift rail as well as an output cam shaft cutout in at leastone other output shift rail having a one-way cam follower surfaceadapted to cooperate with their respective one-way cams to effect axialmovement of the respective shift rails in one and the same directionupon both clockwise and counterclockwise oscillation of said one-waycams, said one-way cam follower surfaces also being adapted toalternately cooperate with said interlock cams to arrest the respectiveshift rails against axial movement upon oscillation of said cams; i.means for actuating all of said cams, by motion of a hand-actuated shiftlever; j. interlock system means between said input and output cams foractuating all of said input cams and all of said output cams in apredetermined sequential order; and k. said plurality of input andoutput shift rails being so arranged that said input and outputinterlock cams cooperate with all but the selected ones of the input andoutput shift rails of said multiple transmission inputs and saidmultiple transmission outputs.
 14. The transmission control system ofclaim 13 where each one-way cam includes substantially similar upper andlower cam operating surfaces, each of which has a tooth portion and acam end surface.
 15. The transmission control system of claim 14 whereineach one-way cam follower surface includes substantially similar upperand lower cam follower notches, with each notch having a shift railadvancing surface and a shift rail disengaging surface.
 16. Thetransmission control system of claim 15 wherein said cam tooth portionis adapted to cooperate with said shift rail advancing surface and saidcam end surface is adapted to cooperate with said shift rail disengagingsurface.
 17. The transmission control system of claim 16 wherein thedirection of movement of one of said other input and output shift railscan be reversed by rotating one of said one-way cams and its associatedone-way cam follower surface 180° around the vertical centerline of theassociated one of said cam shafts.
 18. The transmission control systemof claim 15 wherein each one-way cam and its associated cam followersurface are symmetrical about a horizontal plane containing the axes ofsaid cam shafts.
 19. In combination with a speed change transmissionhaving a gear train that is characterized by having at least two inputsand at least two outputs and having pluralities of input and outputshift rails to effect speed changes; transmission control comprising:a.an axially movable and oscillatable shaft; b. a two-way cam; c. aone-way cam; d. an interlock cam, with all of said cams beingselectively spatially arranged on said shaft so as to slide andoscillate in unison therewith, said cams being adapted to cooperate withsaid input and output shift rails; e. every input and output shift railhaving a cutout in alignment with said shaft so as to permit passagetherethrough of said shaft; f. a two-way cam follower surface in atleast one of said cutouts adapted to cooperate with said two-way cam toeffect axial movement of the respective shift rails in one directionupon clockwise oscillation of said two-way cam and alternately to effectaxial movement in an opposite direction upon counterclockwise rotationof said two-way cam, said two-way cam follower surface also beingadapted to alternately cooperate with said interlock cam to arrest thecooperating shift rail against axial movement upon oscillation of saidcams; g. a one-way cam follower surface in at least one other of saidcutouts adapted to cooperate with said one-way cam to effect axialmovement of the respective shift rails in one and the same directionupon both clockwise and counterclockwise oscillation of said one-waycam, said one-way cam follower surface also being adapted to alternatelycooperate with said interlock cam to arrest said cooperating shift railagainst axial movement upon oscillation of said cams; h. means foractuating, via sliding and oscillating, all of said cams by motion of ahand-actuated shift lever; and i. said plurality of input and outputshift rails being arranged so that said interlock cam cooperates with anonselected one of the input and output shift rails.
 20. Thetransmission control system of claim 19 wherein said one-way camincludes substantially similar vertically opposed cam operatingsurfaces, each of which has a tooth portion and a cam end surface. 21.The transmission control system of claim 20 wherein said one-way camfollower surface includes substantially similar vertically opposed camfollower notches, with each notch in turn having a shift rail advancingsurface and a shift rail disengaging surface.
 22. The transmissioncontrol system of claim 21 wherein the center points of said cam endsurfaces and the leading edges of said tooth portions are offsetrelative to a vertical center line of said shaft in order to permitinteraction of said cam end surface with respect to said shift raildisengaging surface.
 23. The transmission control system of claim 22wherein said one-way cam and said one-way cam follower surfaces aresymmetrical about a horizontal plane containing the axis of said shaft.24. The transmission control system of claim 22 wherein each one-way camfollower surface includes opposed side surfaces that are adapted tocooperate with said interlock cam in the absence of said one-way cam.